"We know that women have lower workforce participation rates than men, we know that they tend to be in part-time or casual work, that they undertake the majority of unpaid caring work and we also know that because women move in and out of the paid workforce as a result of their caring responsibilities, that there's a significant inequality in their earning capacity.

"And what it means is that women's rights to economic security are unrealised and they're less likely to be engaged and as fully productive as they can be in the workforce."

In Australia, women's wages are around 65 per cent that of men's.

Oxfam is calling on all G20 nations to step up efforts for a more inclusive society, and for Australia to show leadership at the G20 conference to be held in Brisbane later this year.

"What the report shows is that the G20 countries are variable in terms of how they're dealing with issues to do with women's pay and women's participation and women's contribution to life in general," Dr Szoke said.

Dr Szoke says while some countries are making efforts to close the gender gap there is "really a lack of ability or attention to actually putting in policies that ensure that gender equality exists".

"Some countries are better in terms of pay equity, others have still got a long way to go in terms of recognising things like unpaid work and ensuring that women's voices are heard in public activities," she said.

"Oxfam's report has been released at this time as we head toward the G20 in Australia because we think there are really three things that the G20 could do in terms of honouring their commitment to tackle the barriers to women's full economic and social participation.

"Those things are to look much more at fiscal and employment policies, but also to recognise things such as unpaid work and to ensure that there are appropriate protections that are put in place to release women to be able to make their contribution to the economy."

She says recognition of these contributions would mean G20 goals are better realised.

"If we had equal pay for equal work it means that the employment areas that are currently, if you like gendered - for example women are often in caring roles - [they] would be appropriately remunerated...[and] it would mean that we actually have women participating fully in the economic growth of the economy," Dr Szoke said.

"What we know is that if we are to achieve the growth agenda which is the aspiration of the G20, then we need to make sure that all people can participate.

"That in a fact we want inclusive growth and what we know is that there's very strong evidence that strong development, inclusive growth and women's rights are all very closely linked."

Editor's note: The original item stated it would take Australian women more than 70 years to reach pay equality. However, the original assessment by the International Labour Organisation covers the global population of women, not just those who are Australian.